Clinical outcomes of using 4 + 5 extensor compartment pedicled vascularized bone graft in Kienböck's disease.

BACKGROUND

This study aimed to evaluate the mid-term clinical and radiological outcomes of a 4th-5th extensor compartment artery (4 + 5 ECA) pedicled vascularized distal radius bone graft in patients with Lichtman stage II and IIIa Kienböck's disease, with a particular focus on differences between disease stages and magnetic resonance imaging (MRI) evidence of lunate revascularization.

METHODS

A retrospective review was conducted on 30 patients (31 wrists) treated with a 4 + 5 ECA pedicled vascularized bone graft between 2022 and 2024. Nineteen wrists were classified as Lichtman stage II and 12 as stage IIIa. Clinical evaluation included visual analog scale (VAS) pain score, Mayo Wrist Score, wrist range of motion, and grip strength. Radiological assessment comprised plain radiographs and MRI, evaluating Lichtman stage progression, carpal height ratio, Stahl index, and MRI signal changes suggestive of revascularization. Preoperative and final follow-up results were compared within and between stage subgroups.

RESULTS

The mean follow-up duration was 27.5 months. In the entire cohort, VAS pain scores significantly decreased (6.1 to 2.6) and Mayo Wrist Scores significantly improved (36.4 to 68.4) (p < 0.05). Grip strength increased from 55.2% to 70.6% of the contralateral side. Clinical improvements were significantly greater in stage II patients than in stage IIIa patients. MRI findings consistent with lunate revascularization were observed in 21.1% of stage II wrists, whereas no clear revascularization was detected in stage IIIa wrists. Disease progression occurred in 29.0% of all cases, more frequently in stage IIIa wrists.

CONCLUSIONS

The 4 + 5 ECA pedicled vascularized bone graft is a safe and effective treatment for early-stage Kienböck's disease, providing significant pain relief and functional improvement. Clinical and radiological outcomes are more favorable in Lichtman stage II patients, supporting early surgical intervention with appropriate indications.